Effects of injection of acetic acid and propionic acid for total phosphorus removal at high temperature in enhanced biological phosphorus removal process

2014 ◽  
Vol 69 (10) ◽  
pp. 2023-2028 ◽  
Author(s):  
C. Y. Ki ◽  
K. H. Kwon ◽  
S. W. Kim ◽  
K. S. Min ◽  
T. U. Lee ◽  
...  

In summer, wastewater treatment plant total phosphorus (TP) removal efficiency is low in South Korea. The reason is because of high temperatures or significant fluctuation of inflow characteristics caused by frequent rainfall. Hence, this study tried to raise TP removal efficiency by injecting fixed external carbon sources in real sewage. Polyphosphate accumulating organisms (PAOs) and glycogen accumulating organisms (GAOs) compete to occupy microorganisms at high temperature. Propionate is known to restrain GAOs. Thus, acetate and propionate were chosen as the external carbon source in this study to find out the suitable volume and ratio of carbon source which ensured the dominance of PAOs. An external carbon source was supplied in the anaerobic reactor of the biological phosphorus removal process at high temperature (above 25 °C). TP removal efficiency was improved by injecting an external carbon source compared to that without an external carbon source. Also, it remained relatively stable when injecting an external carbon source, despite the variation in temperature. TP removal efficiency was the highest when injecting acetate and propionate in the proportion of 2:1 (total concentration as chemical oxygen demand (COD) is 12 mg/L in influent).

2004 ◽  
Vol 49 (5-6) ◽  
pp. 257-264 ◽  
Author(s):  
S.R. Chae ◽  
S.H. Lee ◽  
J.O. Kim ◽  
B.C. Paik ◽  
Y.C. Song ◽  
...  

As the sewerage system is incomplete, sewage in Korea lacks easily biodegradable organics for nutrient removal. In this country, about 11,400 tons of food waste of high organic materials is produced daily. Therefore, the potential of food waste as an external carbon source was examined in a pilot-scale BNR (biological nutrient removal) process for a half year. It was found that as the supply of the external carbon increased, the average removal efficiencies of T-N (total nitrogen) and T-P (total phosphorus) increased from 53% and 55% to 97% and 93%, respectively. VFAs (volatile fatty acids) concentration of the external carbon source strongly affected denitrification efficiency and EBPR (enhanced biological phosphorus removal) activity. Biological phosphorus removal was increased to 93% when T-N removal efficiency increased from 78% to 97%. In this study, several kinds of PHAs (poly-hydroxyalkanoates) in cells were observed. The observed PHAs was composed of 37% 3HB (poly-3- hydroxybutyrate), 47% 3HV (poly-3-hydroxyvalerate), 9% 3HH (poly-3-hydroxyhexanoate), 5% 3HO (poly-3-hydroxyoctanoate), and 2% 3HD (poly-3-hydroxydecanoate).


1996 ◽  
Vol 34 (1-2) ◽  
pp. 285-292 ◽  
Author(s):  
P. R. Thomas ◽  
D. Allen ◽  
D. L. McGregor

This study was undertaken to optimise phosphorus removal by incorporating a chemical dosing facility in an existing biological nutrient removal activated sludge plant at Albury in Australia. Results of pilot plant trials and jar tests indicated that both alum and ferric chloride successfully reduced the orthophosphate concentrations with only a minor variation in the chemical costs. However, alum was chosen as the preferred chemical for use in the full-scale plant and tests showed that alum precipitation combined with biological nutrient removal lowered the orthophosphate (ortho-P) concentrations to as low as 0.01 mg/L with average total phosphorus (total-P) levels of around 0.5 mg/L. It is concluded that maximising total phosphorus removal in the treatment plant would require optimising biological phosphorus removal, applying correct chemical dosages to varying mixed liquor orthophosphate concentrations, adequate mixing, suitable pH values and minimising suspended solids in the clarifier effluent.


2010 ◽  
Vol 61 (7) ◽  
pp. 1837-1843 ◽  
Author(s):  
Q. Yuan ◽  
R. Sparling ◽  
P. Lagasse ◽  
Y. M. Lee ◽  
D. Taniguchi ◽  
...  

An enhanced biological phosphorus removal process (EBPR) was successfully operated in presence of acetate. When glycerol was substituted for acetate in the feed the EBPR process failed. Subsequently waste activated sludge (WAS) from the reactor was removed to an off-line fermenter. The same amount of glycerol was added to the WAS fermenter which led to significant volatile fatty acids (VFA) production. By supplying the system with the VFA-enriched supernatant of the fermentate, biological phosphorus removal was enhanced. It was concluded that, if glycerol was to be used as an external carbon source in EBPR, the effective approach was to ferment glycerol with waste activated sludge.


2012 ◽  
Vol 550-553 ◽  
pp. 2329-2332
Author(s):  
Jun Li ◽  
Tao Tao ◽  
Xue Bin Li ◽  
Jiong Hui Li

A pilot-scale modified SBR process was used to treat urban wastewater. The average NH4+-N efficiency removal was 98 %. The average TN removal efficiency was 52 %. The average TP removal efficiency was 85 %. The average COD removal efficiency was 85 %. The average effluent NH4+-N was 0.34 mg/L. The average effluent TN was 12 mg/L. The average effluent phosphorus was 0.75 mg/L. The average effluent COD was 35 mg/L. The result shows that the increase of 100 mg/L MLSS concentrations by proliferation or decrease of 100 mg/L MLSS concentrations by discharging residual sludge can remove 1 mg/L total phosphorus from wastewater. The faster the MLSS increases, the higher efficiency the phosphorus removal is achieved. When MLSS is fluctuating or decreasing, the phosphorus removal would be worse than MLSS increase. When MLSS increases 500 mg/L everyday, phosphorus removal efficiency would be very high; the average phosphorus removal efficiency would be higher than 90 % in the most urban wastewater treatment plant.


Sign in / Sign up

Export Citation Format

Share Document